Eco-comfort technology makes these systems smarter in how they use energy and minimizes their impact on the environment. Plus there are many advanced features like the i-see™ Sensor, that automatically detects room temperature differences and adjusts for greater comfort. Mitsubishi Electric's advanced multi-stage filtration systems dramatically reduce allergens and help eliminate odors. And our indoor units operate with sound levels starting as low as 19dB(A). That sound is even quieter than a human whisper.